Alex DeMetrick has details on the National Transportation Safety Board’s new involvement.

If safety improvements need to be made to the Bay Bridge, the state says it’s open to NTSB recommendations.

What sent this car and its driver into the bay is clear from witnesses who saw the accident last week on the Bay Bridge.

“It was hit by an 18-wheeler really badly and the 18-wheeler just pushed it right over the wall,” a 911 caller said.

A 40 foot plunge that 22-year-old Morgan Lake survived.

“The car hit the water. My mouth filled up with water. The car was sinking faster than I expected,” Lake said.

Maryland’s Transportation Authority police are the lead agency investigating the accident. But it was AAA Mid-Atlantic that pushed for the NTSB to take a closer look at the barrier walls.

“Making sure that the specifications, regarding height specifically, are strong enough so that a car will not go over the bridge if they’re involved in an accident,” said Regina Averella, AAA Mid-Atlantic.

“My instructions to our agencies are to work very closely with the NTSB. We welcome their involvement,” said Governor Martin O’Malley.

And starting Thursday, NTSB investigators joined the state in a safety probe. The NTSB’s provided input in the past on the bridge, helping form the rules Maryland already follows.

“We are in compliance with basically federal standards for those types of barriers that are used commonly on bridges throughout the country,” said Bruce Gartner, Acting Sec. MTA.

Traffic volume on the bridge varies from year to year.

In 2003, the average was over 34,000 vehicles a day. It peaked in 2007 with more than 37,000. And last year, it was down to just under 36,000. But overall:

“We have a congestion problem. And as traffic increases, we really need to take a look to see if there are options for another span,” said Hershey.

“Whatever the experts and the engineers and the architects say, I think we should follow their advice and direction,” the governor said.

Since the Bay Bridge was built, designs for new bridges have incorporated higher barrier walls.

No time frame has been set on issuing a report on recommendations for safety improvements on the bridge.